Needle stripper foot for sewing machines



Sept. 1953 R. E. JOHNSON NEEDLE STRIPPER FOOT FOR SEWING MACHINES Filed Ad 51, 1951 v INVENTOR. Ralph E. Johnson BY ATTORNEY WITNESS m ziu Patented Sept. 22, 1953 NEEDLE STRIPPER FOOT FOR SEWING MACHINES Ralph E. Johnson, Mountainside, N. J., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application August 31, 1951, Serial No. 244,547

7 Claims.

This invention relates to a sewing machine attachment and more particularly to a needle stripper foot for use in darning or embroidering operations.

' An object of this invention is to provide an improved stripper foot which will permit free horizontal motion of the work piece when the sewing needle is out of the work.

Another object of the invention is to provide a simple form of stripper foot for attachment to a presser-bar and which will yield upwardly to permit diiierent thicknesses of work material to pass under the stripper foot without raising the presser-bar.

A further object is to provide a stripper foot which may be attached to a presser bar and arranged to yield downwardly when the presserbar is raised and the needle-bar interferes with the stripper foot at the bottom of the needle stroke.

In the drawing, Fig. 1 is a partial end view in elevation of a sewing machine having the needle stripper foot attached to the presser-bar.

Fig. 2 is an enlarged side view in elevation of the needle stripper foot.

Fig. 3 is an enlarged sectional view of the stripper foot taken on line 3--3 of Fig. 2.

Fig. 4 is an enlarged rear perspective view of the stripper foot with the sliding cover removed.

Fig. 5 is an enlarged rear perspective view of the sliding cover for the stripper foot.

Referring to the drawings, a needle stripper foot assembly is shown attached to a presser bar ll of a sewing machine Q2. The presser bar Il may be raised either manually or automatically by any conventional presser-bar lifting mechanism, such as the device shown in U. S. Patent No. 2,009,194, issued to P. Hleb. A reciprocatory needle-bar I3 is carried by the head It of the sewing machine l2 and may be driven by the usual sewing machine mechanism. A conventional needle clamp l5 and thread guide I6 is carried by the lower end of the needle-bar l3. Located beneath a work support I! of the sewing machine is a conventional loop-taker 18 a which cooperates with the needle l9 to form stitches.

The needle stripper foot assembly l0 comprises a support member or body strip 20 having each end bent forwardly to form an ear provided with a rectangular aperture 2 l. The apertures 2| are alined and receive a shank portion 22 of a stripper foot 23. A slotted member 24 extends rearwardly from the body strip 20 and is bent to form an attaching member which is engaged by a clamping screw 25 carried by the presserbody strip to support one end of a coil spring 28.

The free end 21 of the ear 26 is provided with a hole 29 which loosely receives one end of the coil spring 28. The spring 28 passes through the center of en elongated hole 30 in the body strip and is fastened in a hole 3| in the stripper foot shank portion 22. the stripper foot provides an opening for the needle I9 to pass through during sewing operations. The front and side portions of the stripper foot assembly are enclosed by a cover 33 formed with a guide lip 34 along one edge. The opposite edge of the cover is formed with a latch button 35 and a finger notch 36. When the device is assembled, the cover 33 slides over the body strip 20 with the guide lip 34 engaging the rear surface of the body strip until the latch button 35 drops between the attaching member 24 and the ear 26. The cover is then locked in place. The cover is removed by inserting a finger in the notch 36 to lift the side of the cover 33 carrying the latch button 35. When the latch button is raised sufiiciently, the cover may be pushed endwise and removed.

From the foregoing description, the operation of the device will be readily understood. As described above, the coil spring 28 loosely engages the free end 27 of ear 26 and is fastened in the shank portion 22 of the stripper foot. The spring is relatively stiff and is designed to flex laterally. Since the spring passes through the center of the elongated hole 30 when'it is in its neutral or unfiexed position, the stripper foot 23 is yieldingly held in a neutral position which is its normal rest position. When in this neutral position, the lower surface of the stripper foot is located about of an inch above the surface of the work support I! with the presserbar in its lowered position, as shown in Fig. 1.

The clearance provided between the stripper foot 23 and the work support I! is sufliclent to permit free movement of a normal thickness of work material between the two members without lifting the stripper foot. The stripper foot holds the work in place to prevent it from flagging. However, should an unusual thickness of material be encountered, such as a heavy seam, the spring 28 will flex upwardly and permit the stripper foot 23 to rise and allow the thick portion to pass under the foot 23. The horizontally disposed coil spring 28 is purposely made weaker A clearance hole 32 in' than the usual presser spring shown in the l-Ileb Patent No. 2,009,194, urging the presser-bar downwardly, in order that the presser-bar will remain in its lowest position. If an extremely thick piece of material is encountered, the spring 28 will rise against the upper end of the elongated hole 30 which functions as a stop. When the spring engages the end of the slot, additional raising of the stripper foot will raise the presserbar II in the usual manner. It should be noted that when this stripper foot assembly is used on a machine equipped with an automatic presserbar lifter, as shown in the I-Ileb patent, the action of the automatic lifter is not afiected by varying thicknesses of work material since the stripper foot accommodates any extra thickness of material which is normally encountered without raising the presser-bar.

In order to secure sufiicient clearance under the stripper foot when the presser-bar is in the raised position, the presser-bar H is raised to a height where the stripper foot 23 will interfere with the needle clamp 55 and thread guide l5, should the needle-bar i3 inadvertently be moved to the bottom of its stroke. However, under these conditions, the stripper foot 23 is carried downwardly from its neutral position along with the needle-bar and no damage is done to any of the parts. When the needle-bar rises again, the spring 28 returns the stripper foot 23 to its neutral position. Thus, a large clearance for re moval of the work may be obtained between the needle stripper foot 23 and the work support ll without resulting in inadvertent damage to the sewing machine parts in the event that the needle-bar is lowered.

Having thus set forth the nature of the invention, what I claim herein is:

1. A sewing machine attachment comprising, a support member, a needle stripper foot carried by said support member and reciprocable rectilinearly in opposite directions to either of two extreme positions from a neutral position, said neutral position being the normal rest position of said stripper foot, and a spring engaging said support member and said stripper foot to hold said stripper foot yieldingly in its neutral position.

2. A sewing machine attachment comprising, a support member, a needle stripper foot carried by said support member for reciprocating rectilinear motion to either of two extreme positions from a neutral position, said neutral position being the normal rest position of said stripper foot, a spring interposed between said support member and said stripper foot to hold said stripper foot yieldingly in its neutral position, and stop means engageable by said spring to limit the movement of said stripper foot in each direction.

3. A sewing machine attachment comprising, a support member, a needle stripper foot carried by said support member and rectilinearly reciprocable relative to said support to either of two extreme positions from a neutral position, and a horizontally disposed laterally flexible coil spring engaging said stripper foot and said support member to yieldingly retain said stripper foot in its neutral position.

4. An attachment for sewing machines comprising, a support member provided with a vertical guideway, a stripper foot carried by said guideway and reciprooable therein from a neutral position to either of two extreme positions, said neutral position being the normal rest position.

of said stripper foot, and a spring interposed between said support member and said stripper foot to yieldingly hold said stripper foot in the neutral position.

5. In a sewing machine, a work support, a needle-bar, a reciprocable presser-bar, a stripper foot, a stripper foot support member carried by said presser-bar, said stripper foot being reciprocable from a neutral position toward and away from said work support, said neutral position being the normal rest position of said foot free of said needle-bar and a spring engaging said support member and said stripper foot and yieldingly holding said stripper foot in the neutral position.

6.111 a sewing machine, a work support, a needle-bar, a presser-bar, a stripper foot support carried by said presser-bar, a stripper foot carried by said stripper foot support and reciprocable in either direction from a neutral position, said neutral position being the normal rest position of said foot coil spring means interposed between said stripper foot and said stripper foot support to yieldingly hold said stripper foot in the neutral position, and stop means limiting the motion of said stripper foot.

'7. A sewing machine attachment comprising a stripper foot support provided with guide means and a spring clearance slot, a stripper foot reciprocably mounted in said guide means, and a spring passing approximately through the center of said clearance hole and having its ends engaging said stripper foot and a portion of said stripper foot support respectively, said spring holding said stripper foot yieldingly in a neutral position when relaxed and being engageable with said support at the ends of said clearance slot upon maximum travel of said foot in either direction from said neutral position.

RALPH E. JOHNSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 475,426 Whitney May 24, 1892 1,102,433 Pettit July 7, 1914 1,943,254 Barron Jan. 9, 1934 FOREIGN PATENTS Number Country Date 523,862 Germany Apr. 29, 1931 

